This will be based on whether you are Team Edward or Jacob mostly, but to be honest...
I think her marrying Jake would have been a bad idea because I think eventually she would have started comparing him to Edward "whether it is just dating or as a husband) and she would have been disappointed that it wasn't Edward so she would have been sad often and Jake would have felt bad.
I think Edward was the best choice because she truly loved him and no matter what she couldn't be HER without him in her life. She wouldn't have been sad, except for the obvious reasons.
i honestly think jacob because he would never really leave her like edward did--twice! he's
sooo loyal and edward is always putting her in
situations like ''i won't turn you unless you
marry me.'' but, if edward makes her truly
happy, i guess edward